Chennai: Two-time former singles champion and world No.15 Marin Cilic and Stanislas Wawrinka are set to take part in the 18th Aircel Chennai Open, to be held in Chennai from December 31 to January 6.

The confirmation from these two top-20 players along with participation from World No.6 Tomas Berdych and World No.9 Janko Tipsarevic have ensured that the tournament will have one of the strongest fields in its history.

Cilic, the 6ft 6 inch Croatian, won the singles titles here in 2009 and 2010. He was in the 2012 field as the fourth seed but suffered a patella tendon injury, which ruled him out of the tournament as well as the season's first Grand Slam, the Australian Open.

After recovering, the right-hander gained momentum by reaching the Munich final in April this year. In July, he captured his eighth ATP World Tour title at the ATP Vegeta Croatia Open Umag.

The 24-year-old Cilic, who has begun five previous seasons in Chennai, registered his career high ATP ranking of 9 on February 22, 2010 with his best-ever performance in a Grand Slam, reaching the semi-finals in the 2010 Australian Open.

He won his first Chennai Open title in 2009, defeating India's Somdev Devvarman and followed it in 2010, beating Wawrinka in the final.

"I am delighted to be back in Chennai, especially since I could not participate in last year's event due to an injury. I have chosen to start my five previous seasons here and have had great success as a lead up to the Australian Open. It is always a pleasure to play in Chennai, a city that has grown to become a home away from home for me," said Cilic.

Wawrinka, the world ranked 17th from Switzerland, who will also be a part of this season's draw for the fifth straight year, is eyeing a winning start like the previous edition.

Hiten Joshi, CEO of Tamil Nadu Tennis Association said, "It is a privilege to have Marin Cilic back for the 2013 edition. Also it will be good to see Wawrinka back in action this year. We look forward to watching Cilic and Wawrinka showcase their skills this year."

The 18th edition will feature Tom Annear, who has worked at the Sony Open for the last 17 years, as the new Tournament Director.

The USD 4,50,000 championship is India's only and South Asia's premier ATP World Tour Open 250 event. The tournament will be held at the SDAT Tennis stadium in Nungambakkam here.